Laser welding is becoming increasingly important in the automotive industry and quality of the weld is critical for a successful application. In many cases the increase in welding speed provided by laser welding has resulted in the need for an automated, on-line weld monitoring system....

Recent progress in available beam power and beam quality has meant that high power diode lasers may soon become prime tools for welding in many assembly applications in industrial production. Their compact size and low weight makes them particularly suitable for use in conjunction with robotic control. The advantages of laser welding ...

A copper vapor laser (CVL) of 511/578 nm wavelength, 25 ns pulse width, and 10 kHz repetition rate combined with a computer controlled galvo head was used for laser micromachining of 304 stainless steel. The objective of this study was to develop the CVL micromachining process and its optimization. We observed a significant improvement in micromachining quality with a spatially filtered ...

Radiation power and image size of the source on the viewer's retina (apparent source) determines the hazard for the eye. Following IEC 60825-1, the effective emission limits are dependent on the tabulated accessible emission limits and the assigned measurement conditions—both depending on the source size. In the case of a light emitting diode (LED), this emitting area is not only determined by the chip size but also by the housing—due to built-in lenses, reflectors, and scattering materials. Also the virtual source position will be distorted by the integrated lenses. Since the measurement distance ...

A sample holding method is newly developed for laser forming, in which the target material is held between two transparent plates. During laser beam scanning on the target, the target foil is kept flat. After the scanning is finished, the foil is detached from the holder; the foil bends toward the beam scanned surface. Experiments are carried out with a Nd:yttrium–aluminum–garnet laser beam for a spot size of 25μm and for a traverse speed of 10 mm/s. A bending...

Laser surface treatments of titanium in air have been performed through a pulsed Nd:yttrium–aluminum–garnet (λ=1.064 μm) laser. Several samples have been obtained modifying the laser scan velocity and partial overlapping of consecutive traces, in order to study the influence of these parameters on the surface morphology. Scanning electron microscopy and profilometry measurements have revealed different surface morphologies depending on the physical processes involved in th...

Mold-less forming produces precise metal parts by thermal variation generated used high power beam irradiation. Some technologies like the laser and the plasma arc have proved to fit the requirements of this new forming technique [M. Geiger and F. Vollersten, Ann. CIRP 42, 301–304 (1993); P. J. Li et al., J. Eng. Manuf. Proc. Part B 214, 0954–4054 (2000)], which can be applied both for rapid prototyping and rapid manufacturing. In particular, a complex shape can be generated using curved path for the irradiating strategy o...

The combination of plasma arc with a Nd:YAG laser during surface alloying produces a synergistic effect which significantly increases the depth of the melt pool beyond that expected by a summation of the individual depths. Incremental increases in laser power produce ...

Laser-based instruments are used in areas where coal dust ignition presents a safety hazard. The National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory (NIOSH, PRL) is conducting a study to help determine when an optical beam may be considered a potential ignition source in underground coal mines or coal storage facilities. Researchers conducted experiments to determine threshold igniting powers for Pittsburgh seam bituminous co...